Parasitological diagnosis in food fish produced in a fish farm, in the Zona da Mata, Minas Gerais, southeastern Brazil / Diagnóstico parasitológico em peixes para consumo produzidos em uma psicultura, na Zona da Mata, Minas Gerais, região sudeste do Brasil

Abstract This study identified the parasitic species in juvenile freshwater finfishes during the fattening stage, from a fish farm located in the Zona da Mata (MG), southeastern Brazil, and revealed both macro and microscopical lesions in fish gills. A total of 172 juvenile fishes of different species (Oreochromis niloticus, Ictalurus punctatus, Ctenopharyngodon idella, Cyprinus carpio, Astyanax bimaculatus and Brycon amazonicus) were transported to a laboratory in São Paulo city. The fish were sedated and then euthanized for parasitological analysis. All fish were infected by at least one parasite species. Ten different species of parasites were identified: Apiosoma sp., Epistylis sp., Ichthyobodo sp., trichodinids, Piscinoodinium pillulare, Ichthyophthirius multifiliis, Tetrahymena sp., monogeneans, Centrocestus formosanus metacercariae, and Dermocystidium sp. The best management practices and lack of sanitary control were also discussed.

Resumo Este trabalho identificou espécies parasitas em peixes de produção juvenis de água doce, durante a fase de engorda, oriundos de uma piscicultura da Zona da Mata (MG), na região sudeste do Brasil, além das lesões de brânquias, causadas tanto macro quanto microscopicamente. Um total de 172 peixes juvenis de diferentes espécies (Oreochromis niloticus, Ictalurus punctatus, Ctenopharyngodon idella, Cyprinus carpio, Astyanax bimaculatus e Brycon amazonicus) foram transportados para um laboratório na cidade de São Paulo. Os peixes foram anestesiados e eutanasiados para análise parasitológica. Todos os peixes estavam acometidos por pelo menos uma espécie de parasito. Dez diferentes espécies de parasitos foram identificadas: Apiosoma sp., Epistylis sp., Ichthyobodo sp., tricodinídeos, Piscinoodinium pillulare, Ichthyophthirius multifiliis, Tetrahymena sp., monogeneas, metacercárias de Centrocestus formosanus e Dermocystidium sp. As boas práticas de manejo e inadequado controle sanitário também foram discutidos.

New occurrence of Kudoa orbicularis parasitizing the freshwater catfish Trachelyopterus galeatus (Siluriformes: Auchenipteridae) in the Brazlian Amazon region / Nova ocorrência de Kudoa orbicularis parasitando peixe de água doce Trachelyopterus galeatus (Siluriformes: Auchenipteridae) na região Amazônica brasileira

Abstract The aim of this was describe an infection by Kudoa orbicularis in freshwater catfish Trachelyopterus galeatus. A sample of 80 specimens of T. galeatus was collected in the municipality of Cachoeira do Arari, Marajó Island, in the state of Pará, Brazil. Pseudocysts were found in the muscle fibers of the epaxial and hypaxial regions of 85.0% of the specimens analyzed, reflecting a high infection rate. The pseudocysts contained spores that were pseudo-square in shape, with a mean length of 4.65 µm (range: 4.04-5.54) and mean width of 1.53 µm (1.56-1.74). Analyses on the morphology of the spores and a partial 934-bp sequence of the SSU rDNA gene confirmed that the microparasite was Kudoa orbicularis. This is the second record of this microparasite in a siluriform host in the Brazilian Amazon region.

Resumo O objetivo deste estudo foi descrever a infecção por Kudoa orbicularis em Trachelyopterus galeatus. Foram analisados 80 espécimes de T. galeatus capturados no município de Cachoeira do Arari, ilha de Marajó, estado do Pará, Brasil. A presença de pseudocistos nas fibras musculares das regiões epiaxial e hipoaxial em 85,0% dos exemplares analisados, mostra alto grau de infecção. Os pseudocistos continham esporos de formato pseudoquadrado, medindo 4,65 (4,04-5,54) µm de comprimento e 5,25 (4,78-5,98) µm de largura, com quatro cápsulas polares de tamanho iguais medindo 2,22 (2,05-2,32) µm de comprimento e 1,53 (1,56-1,74) µm de largura. Através das análises morfológicas dos esporos e molecular de uma sequência parcial de 934bps do gene SSU rDNA, confirma que o microparasito é Kudoa orbicularis, sendo este o segundo registro desse microparasito em hospedeiro da ordem Siluriformes da Amazônia brasileira.

Neobenedenia melleni (Monogenea: Capsalidae) in ornamental reef fish imported to Brazil / Neobenedenia melleni (Monogenea: Capsalidae) em peixes ornamentais de recife importados para o Brasil

Abstract The capsalid monogenean Neobenedenia melleni is known as a lethal pathogen for captured marine teleost ornamental fish, if left untreated. This study reports the occurrence of N. melleni parasitizing four species of ornamental reef fish imported into Brazil and maintained in quarantine: Arabian angelfish (Pomacanthus asfur ), yellowbar angelfish (Pomacanthus maculosus), regal angelfish (Pygoplites diacanthus), and bluecheek butterflyfish (Chaetodon semilarvatus). Ten days after the beginning of quarantine, some fish showed behavioral alterations, such as irritability, and corneal opacity, which were rapidly diagnosed to be caused by monogenean parasites by body surface scraping. The fish from the same batch were treated with two applications of 2 mg L-1 praziquantel each at an interval of four days. Seven days after the first treatment, the mucus surface of the fish was re-examined, which did not reveal the parasites presence being delivered for commercialization.

Resumo Neobenedenia melleni é conhecido como um parasito letal para peixes teleósteos ornamentais marinhos capturados se não tratado. Este estudo relata a ocorrência de N. melleni parasitando quatro espécies de peixes ornamentais importados para o Brazil: Arabian angelfish (Pomacanthus asfur), yellowbar angelfish (Pomacanthus maculosus), regal angelfish (Pygoplites diacanthus) e bluecheek butterflyfish ( Chaetodon semilarvatus). Dez dias depois do início da quarentena, foram observados irritabilidade e opacidade na córnea dos peixes que, foram diagnosticadas com N. melleni na superfície corporal. Todos os peixes foram tratados com duas aplicações de praziquantel 2 mg L-1 em intervalo de quatro dias. Sete dias após o início do tratamento, um novo exame parasitológico foi realizado o qual não revelou a presença dos parasitos, sendo liberados para comercialização.

Inter-laboratory ring trial to evaluate real-time reverse transcription polymerase chain reaction methods used for detection of infectious pancreatic necrosis virus in Chile

Background: Infectious Pancreatic Necrosis Virus (IPNV) is the etiological agent of a highly contagious disease that affects salmonids. In Chile, the second worldwide salmon producer, IPNV causes great economic loss and is one of the most frequently detected pathogens. Due to its high level of persistence and the lack of information about the efficiency of its diagnostic techniques, the National Reference Laboratory (NRL) for IPNV in Chile performed the first inter-laboratory ring trial, to evaluate the sensitivity, specificity and repeatability of the qRT-PCR detection methods used in the country. Results: Results showed 100% in sensitivity and specificity in most of the laboratories. Only three of the twelve participant laboratories presented problems in sensitivity and one in specificity. Problems in specificity (false positives) were most likely caused by cross contamination of the samples, while errors in sensitivity (false negatives) were due to detection problems of the least concentrated viral sample. Regarding repeatability, many of the laboratories presented great dispersion of the results (Ct values) for replicate samples over the three days of the trial. Moreover, large differences in the Ct values for each sample were detected among all the laboratories. Conclusions: Overall, the ring trial showed high values of sensitivity and specificity, with some problems of repeatability and inter-laboratory variability. This last issue needs to be addressed in order to allow harmonized diagnostic of IPNV within the country. We recommend the use of the NRL methods as validated and reliable qRT-PCR protocols for the detection of IPNV.

Morphological and molecular diagnosis of Pseudoterranova decipiens (sensu stricto) (Anisakidae) in imported cod sold in Brazil / Diagnose morfológica e molecular de Pseudoterranova decipiens (sensu stricto) (Anisakidae) em bacalhau importado vendido no Brasil

An anisakid nematode larva found in cod sold in the state of Minas Gerais, Brazil was studied by light and scanning electron microscopy and by a molecular approach. Mitochondrial cytochrome c-oxidase subunit 2 (mtDNA cox-2), 28S rRNA and ITS1, 5.8S and ITS2 regions were amplified using the polymerase chain reaction and sequenced to evaluate the phylogenetic relationships of the larva. The genetic profile confirmed that this larva belongs to the species Pseudoterranova decipiens (sensu stricto). This is the first molecular and ultrastructural study of Pseudoterranova decipiens (sensu stricto) in imported cod sold in Brazil. The health implications of these findings are discussed.

Uma larva de Nematoda anisakídeo encontrada em bacalhau comercializado no Estado de Minas Gerais, Brasil foi estudada por microscopias de luz e eletrônica de varredura e por uma abordagem molecular. As regiões da subunidade 2 da citocromo c-oxidase mitocondrial (mtDNA cox-2), 28S rRNA e ITS1, 5.8S e ITS2 foram amplificadas usando a reação em cadeia da polimerase e sequenciadas para avaliar as relações filogenéticas da larva. O perfil genético confirmou que esta larva pertence à espécie Pseudoterranova decipiens (sensu stricto). Esse é o primeiro estudo molecular e ultraestrutural de Pseudoterranova decipiens (sensu stricto) de bacalhau importado vendido no Brasil. As implicações destes resultados para a saúde são discutidas.

Protozoan infections in farmed fish from Brazil: diagnosis and pathogenesis / Infecções por protozoários em peixes cultivados no Brasil: diagnóstico e patogênese

The Phylum Protozoa brings together several organisms evolutionarily different that may act as ecto or endoparasites of fishes over the world being responsible for diseases, which, in turn, may lead to economical and social impacts in different countries. Apart from the recent advances for the diagnosis of fish diseases in Brazil, little is known on the protozoan parasites and their relationship with environment and host. This revision presents the most important protozoan parasites found in farmed fish from Brazil, not only with emphasis on its diagnosis, biology, transmission and host-parasite relationship, but also on some information that may be useful to researchers in determining the correct diagnosis in fish farms.

O filo Protozoa reúne diversos organismos evolutivamente distintos que podem atuar como ecto ou endoparasitos de peixes em todo o mundo, sendo responsáveis por doenças as quais, por sua vez, podem ocasionar impactos econômico e social nos diferentes países. Apesar dos recentes avanços no campo de diagnóstico de doenças em peixes no Brasil, ainda pouco se conhece sobre a fauna de protozoários parasitos de peixes e suas relações com o ambiente e hospedeiro. Esta revisão apresenta os mais importantes protozoários parasitos encontrados em peixes cultivados no Brasil, não apenas com ênfase no seu diagnóstico, biologia, transmissão e relação hospedeiro-parasito, mas também algumas informações que podem ser úteis para pesquisadores para o correto diagnóstico em pisciculturas.

Development of a multiplex PCR assay to detect Edwardsiella tarda, Streptococcus parauberis, and Streptococcus iniae in olive flounder (Paralichthys olivaceus)

A multiplex PCR protocol was established to simultaneously detect major bacterial pathogens in olive flounder (Paralichthys olivaceus) including Edwardsiella (E.) tarda, Streptococcus (S.) parauberis, and S. iniae. The PCR assay was able to detect 0.01 ng of E. tarda, 0.1 ng of S. parauberis, and 1 ng of S. iniae genomic DNA. Furthermore, this technique was found to have high specificity when tested with related bacterial species. This method represents a cheaper, faster, and reliable alternative for identifying major bacterial pathogens in olive flounder, the most important farmed fish in Korea.

Micobacteriose por Mycobacterium marinum em "linguado" Paralichthys orbignyanus e em "barber goby" Elacatinus figaro: diagnóstico histopatológico e imuno-histoquímico / Micobacteriosis by Mycobacterium marinum in Brazilian flounder Paralichthys orbignyanus and barber goby Elacatinus figaro: histopathological and imunohistochemical diagnosis

As micobacterioses afetam várias espécies de peixes, tanto comerciais como ornamentais. É uma enfermidade sistêmica com formação de granulomas, conhecida como micobacteriose de peixes. O desenvolvimento da aquicultura tem aumentado o número de casos com essa enfermidade que muitas vezes é de difícil diagnóstico. Neste trabalho apresentamos dois casos de micobacterioses em Paralichthys orbignyanus e Elacatinus figaro provenientes do Laboratório de Piscicultura Estuarina e Marinha da Universidade Federal do Rio Grande (FURG). As micobactérias de peixes possuem menos ácidos graxos que as de mamíferos, por isso foi utilizado o protocolo de coloração de Fite-Faraco, uma vez que o protocolo de coloração clássico de Ziehl Neelsen pode resultar em falsos negativos. Para determinar o tipo de micobactéria foi utilizada a imuno-histoquímica com a qual se pode diagnosticar a presença de Mycobacterium marinum. A enfermidade pode ser transmitida para o homem e com esse trabalho ressalta-se a necessidade de fazer o diagnóstico correto e implantar medidas de proteção para as pessoas que estão em contato com os peixes infectados.

Mycobacteriosis affects various species of fish, including those cultured with commercial purposes. It is a chronic systemic with granuloma forming disease known as fish mycobacteriosis. In the last few years the interest of fish culture has been increasing due to the reduction of the natural fish stocks. However the intensification of fish culture has collaborated to the development of diseases such as mycobacteriosis, causing losses due to the chronic characteristics and difficult diagnosis. This study is to report two cases of mycobacteriosis observed at "Laboratório de Piscicultura Estuarina e Marinha of the Universidade Federal do Rio Grande (FURG)", one for Brazilian flounder Paralichthys orbignyanus and another for barber goby Elacatinus figaro. The Fite-Faraco staining protocol was used. Membranes of mycobacterial cells contain a waxy substance composed of mycolic acids. These are ß-hydroxy carboxylic acids with chain lengths of up to 90 carbon atoms. The property of acid fastness is related to the carbon chain length of the mycolic acid found in any particular species. The fish mycobacterium is much less acid and alcohol fast than the tubercle bacillus and the classic Ziehl-Neelsen Staining Protocol may give false results. The presence of mycobacterial antigen lesions was studied by immunohistological methods using monoclonal antibodies to Mycobacterium marinum. Humans may be infected by these bacteria and develop cutaneous granuloma. In this paper the necessity is stressed for a correct diagnosis of the disease, contributing to the prevention of its establishment in aquatic facilities, and thus, preserving cultured fish as well as human beings from infection.

Molecular Identification and Real-time Quantitative PCR (qPCR) for Rapid Detection of Thelohanellus kitauei, a Myxozoan Parasite Causing Intestinal Giant Cystic Disease in the Israel Carp

Intestinal giant-cystic disease (IGCD) of the Israel carp (Cyprinus carpio nudus) has been recognized as one of the most serious diseases afflicting inland farmed fish in the Republic of Korea, and Thelohanellus kitauei has been identified as the causative agent of the disease. Until now, studies concerning IGCD caused by T. kitauei in the Israel carp have been limited to morphological and histopathological examinations. However, these types of diagnostic examinations are relatively time-consuming, and the infection frequently cannot be detected in its early stages. In this study, we cloned the full-length 18S rRNA gene of T. kitauei isolated from diseased Israel carps, and carried out molecular identification by comparing the sequence with those of other myxosporeans. Moreover, conventional PCR and real-time quantitative PCR (qPCR) using oligonucleotide primers for the amplification of 18S rRNA gene fragment were established for further use as methods for rapid diagnosis of IGCD. Our results demonstrated that both the conventional PCR and real-time quantitative PCR systems applied herein are effective for rapid detection of T. kitauei spores in fish tissues and environmental water.

Development and evaluation of a multiplex PCR assay for simultaneous detection of Flavobacterium psychrophilum, Yersinia ruckeri and Aeromonas salmonicida subsp. salmonicida in culture fisheries

Bacterial cold water disease, enteric red mouth disease and frunculosis are the common bacterial diseases of fish worldwide. The etiologic agents of these diseases are Flavobacterium (F.) psychrophilum, Yersinia (Y.) ruckeri and Aeromonas (A.) salmonicida subsp. salmonicida, respectively. In this study, a multiplex polymerase chain reaction (m-PCR) method with YER8/10-Fer3/4-FP1/3 primer pairs which can identify these fish pathogens simultaneously was developed and optimized. In optimized conditions, neither false specific nor nonspecific amplification occurred. The detection limits of the m-PCR method using DNA extracts from dilutions of pure cultures of bacteria were 35 pg for Y. ruckeri and F. psychrophilum and 70 pg for A. salmonicida subsp. salmonicida. It was determined that 15 CFU Y. ruckeri and F. psychrophilum and 30 CFU A. salmonicida subsp. salmonicida could be detected by m-PCR developed using genomic DNA extracted from dilutions of the suspensions. The detection limits in the presence of tissue debris were 125 CFU for Y. ruckeri and F. psychrophilum and 250 CFU for A. salmonicida subsp. salmonicida. In conclusion, we submit that the m-PCR method developed and optimized in this study can be used for accurate and rapid identification of these bacteria.

Isolation and characterization of Flavobacterium columnare (Bernardet et al. 2002) from four tropical fish species in Brazil / Isolamento e caracterização de Flavobacterium columnare de quatro espécies de peixes tropicais no Brasil

Flavobacterium columnare is the causative agent of columnaris disease in freshwater fish, implicated in skin and gill disease, often causing high mortality. The aim of this study was the isolation and characterization of Flavobacterium columnare in tropical fish in Brazil. Piracanjuba (Brycon orbignyanus), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) and cascudo (Hypostomus plecostomus) were examined for external lesions showing signs of colunmaris disease such as greyish white spots, especially on the head, dorsal part and caudal fin of the fish. The sampling comprised 50 samples representing four different fish species selected for study. Samples for culture were obtained by skin and kidney scrapes with a sterile cotton swabs of columnaris disease fish and streaked onto Carlson and Pacha (1968) artificial culture medium (broth and solid) which were used for isolation. The strains in the liquid medium were Gram negative, long, filamentous, exhibited flexing movements (gliding motility), contained a large number of long slender bacteria and gathered into ‘columns'. Strains on the agar produced yellow-pale colonies, rather small, flat that had rhizoid edges. A total of four Flavobacterium columnare were isolated: 01 Brycon orbignyanus strain, 01 Piaractus mesopotamicus strain, 01 Colossoma macropomum strain, and 01 Hypostomus plecostomus strain. Biochemical characterization, with its absorption of Congo red dye, production of flexirubin-type pigments, H2S production and reduction of nitrates proved that the isolate could be classified as Flavobacterium columnare.

Flavobacterium columnare é o agente etiológico da columnariose em peixes de água doce, ocasionando enfermidade na pele e nas brânquias, provocando freqüentemente um grande número de mortalidade. O objetivo deste estudo foi o isolamento e a caracterização de Flavobacterium columnare em peixes tropicais no Brasil. Piracanjuba (Brycon orbignyanus), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) e cascudo (Hypostomus plecostomus) foram examinados externamente com relação a sinais característicos de columnariose, como manchas acinzentadas na cabeça, região dorsal e pedúnculo caudal dos peixes. A amostragem compreendeu a coleta de 50 exemplares de peixes, representando as quatro diferentes espécies escolhidas para este estudo. Amostras para o isolamento foram obtidas através de raspado com swab estéril das lesões e do rim dos peixes clinicamente diagnosticados como acometidos por columnarios e imediatamente semeados em meios de culturas artificiais (líquido e sólido) próprios para o estudo de Flavobacterium segundo Carlson e Pacha (1968). No meio líquido, houve o desenvolvimento de microrganismos que observados em gota pendente apresentaram a forma de bacilos finos, longos, móveis por deslizamento. Através da coloração de Gram, apresentaram morfologia de bacilos finos, Gram negativos, agrupados em colunas. Em meio sólido, as colônias eram pequenas, cinza-amareladas, com borda em forma de raiz. No total, foram obtidos quatro isolamentos: 01 cepa de Brycon orbignyanus; 01 cepa de Piaractus mesopotamicus; 01 cepa de Colossoma macropomum; e 01 cepa de Hypostomus plecostomus. A caracterização bioquímica das amostras, como absorção do vermelho Congo, produção de flexirrubina, produção de H2S e redução do nitrato, sugere que os isolamentos poderiam ser classificados como Flavobacterium columnare.

First record in South America of Didymosulcus palati and Didymosulcus philobranchiarca (Digenea, Didymozoidae) with new hosts records and pathological alterations

Two species of Didymozoidae, Didymosulcus palati (Yamaguti 1970) and Didymosulcus philobranchiarca (Yamaguti 1970) were reported for the first time in South America, Atlantic Ocean, parasitizing three different tuna species from the coast of Rio de Janeiro, Brazil: Thunnus atlanticus (Lesson), Thunnus albacares (Bonnaterre) and Thunnus obesus (Lowe). Pairs of D. philobranchiarca were found on gill arches of T. albacares and T. obesus, in longitudinal rows of yellow cysts located inside grooves in the hard denticle palate (new site) of the three hosts species studied, and as disperse groups of cysts in the operculum (new site) and gill arches of T. atlanticus (new host record). D. palati occurred as disperse groups of encysted worm pairs in the gill arches of T. albacares and T. obesus and in gill arches and operculum of T. atlanticus (new host record). The pathological alterations induced by D. philobranchiarca in the palate of T. atlanticus are described for the first time. Original measurements and figures are presented.

Pineapple juice for digestion of swamp eel viscera for harvesting infective-stage larva of Gnathostoma spp.

Third-stage larvae were used as antigen in the diagnosis of gnathostomiasis in Western blot analysis. Normally, the larvae were obtained from digestion of eel's liver (Fluta alba) by the enzyme pepsin. We used pineapple juice (Ananus comosus) instead of enzyme pepsin in harvesting Gnathostoma spinigerum third-stage larvae. The difference in recovered larvae numbers, between pineapple juice and pepsin, were not statistically significantly different (p>0.05). The larvae from pepsin and pineapple juice digestion were cultivated on BME for 7 days; the survival rates were not significantly different (p>0.05). Thus, pineapple juice is another enzyme of choice for recovering Gnathostoma spinigerum third-stage larvae.

Puffer fish poisoning: a clinical analysis

To ascertain the clinical manifestations, complications and clinical outcome of Puffer fish poisoning. Setting: The study was carried out in the Department of Medicine and Paediatrics, Khulna Medical College Hospital [KMCH], Khulna, Bangladesh. The period of study ranged from admission of patients till discharge. Subjects and On April 18, 2002, a large number of patients from eight families were admitted to KMCH. A presumptive diagnosis of Puffer fish [tetrodotoxin] poisoning was made on the basis of history of recent consumption of Puffer fishes [Fugu] and classical clinical presentations. The cases were clinically reviewed periodically and routine investigations were done. A total of forty-five persons developed manifestations of Puffer fish poisoning out of which thirty-seven needed hospitalizations. Important symptoms observed were peri-oral tingling sensation [24], weakness of both lower limbs [22], tingling and numbness throughout the body [18], headache [15] etc. Twenty-two patients developed ascending paralysis and 17 of them developed respiratory muscle paralysis. Out of thirty-seven admitted patients twenty-nine improved with conservative treatment. Eight patient died due to respiratory failure. Although Puffer fish is available in our country and Puffer fish poisoning is sporadic, ignorance regarding its proper cooking process may lead to serious clinical hazards including fatality. It has no specific treatment. Health personnel should have sufficient knowledge regarding its clinical manifestations, complications and management. People should be made aware of the potential risk of eating Puffer fish

Doenças de peixes: profilaxia, diagnóstico e tratamento / Illnesses of fish: Prophylaxis, diagnosis and treatment

Publicada pela primeira vez em 1998, esta obra tem como objetivo divulgar, aos profissionais da piscicultura, informações básicas, e de certa maneira com caráter aplicado, sobre as doenças mais importantes que podem comprometer os peixes de água doce quando criados em cativeiro. Esta segunda edição tem algumas modificações em relação à anterior, embora mantenha a mesma organi-zação geral. A cultura de peixes marinhos é cada vez mais importante e, conquanto seja ainda incipiente no Brasil, terá sem dúvida, em médio prazo, uma relevância considerável. Assim, além de outras, foram também incluídas doenças que se manifestam nas pisciculturas marinhas, algumas de grande importância pelo impacto econômico que podem ter nessas explorações. Por outro lado, foram ampliadas as ilustrações fotográficas e incluídas inovações

Métodos de estudo e técnicas laboratoriais em parasitologia de peixes / Methods of study and laboratorial techniques in parasitology of fish

Quando se estudam os parasitas de peixes pode-se ter em mente vários objetivos a serem atingidos, destacando-se aqueles que compreendem os estudos sistemáticos, ecológicos, profiláticos, histopatológicos, ciclos de vida, análise das relações parasitas-hospedeiros, entre outros. Para o seu desenvolvimento, normalmente, são utilizados numerosos métodos e técnicas cujo conhecimento e correta aplicação são fundamentais para que se possam atingir os objetivos inicialmente propostos. Esses instrumentos encontram-se descritos em numerosas publicações dispersas, cuja obtenção nem sempre é uma tarefa fácil. Uma publicação que reunisse os métodos de estudo e técnicas laboratoriais utilizados em parasitologia de preixes poderia ser de grande utilidade para quem se inicia ou já trabalha nesta área da parasitologia